Insulator.



P. S. DUMBOLTON & F. FRANZ.

INSULATOR.

APPLICATION-FILED NOV. 21, 1908. 937,?36. Patented Oct. 19,1909.

IT 8858 INVENTORS PERRY 5. DUMB EIL'IEIN'. FR ANEBCY FEAN z ATTORNE Y8 MLW/ UNITED s Arena orrron.

insnna'ron.

Specification of Letters -retest. 4 Patented Oct, 19, 19., Application flied November 21, 1908. Serial No. 463,739.

To all whom it may concern:

Be it known that we, PERRY S. DUMBoL- TON and FRANK FRANZ, citizens of the United States, residing at Burke, in the county of Shoshone,- State of Idaho, have invented 'an- Improvement in Insulators, of which the following is a specification.

Our invention is an improvement in insulators for telegraph and telephone wires and other similar conductors of electricity.

It is more particularly an improvement in that class of insulators which are mounted on spiral wire coils which are suitably attached to a supporting screw pin. I

Our insulator is adapted for lateral oscillation so that it may be used without danger of breaking,"as is often the case with insulators so'fixed on their supports. as to be incapable of yielding to jar or vibration. This is particularly the case with insulators made of glass or porcelain. In the accompanyin drawing, Figure 1 1s a vertical section 0 our improved insulator and its support. Fig. 2 is an exterior view of the same. Fig. 3 is a bottom plan view. Fig. 4: is a view illustrating the method of detaching the insulator proper from its'support.

The insulator proper 1 has a common and well-known form and is provided centrally with a socket 2 which is conical in form instead of being cylindrical as is usual. in this class of'insulators. That is to say, the socket 2, has the form of a truncated gone, the smaller end being uppermost, and it is formed with a cross screw-thread which receives a screw in the form of a wirejspring 3, the same being connected with the head of a screw pin 4, and the lower end 5 of the spring bein formed with a downward pro jection whic extends normally slightly below the lowest portion of the Insulator proper. It is apparent that when the insulator proper is attached to the suppor t, as shown in Fig. 1, it is free to wcillate or move laterally in anydire'ction so far as permitted by the elasticity of the s ring 3, and the diameter of the socket 2. y this means, the insulator'proper is relieved of jar, vibration, and strain, which otherwise might break it.

It will be understood that in. invention-sis applied more insulators whose body is ma particularly to e of porcelain.

general our A special feature of our invention is the relation of the conical spiral spring 3 to the conical socket, whereby, when the pin 4 of the insulator is screwed into a bar or other support, the spring is compressed to a certain degree so as to fit more tightly in the socket, and, notwithstanding this, the elasticity of the spring is suchthat there is no liability of the insulator proper beingbroken by the expansion ofjthe spring when theinsulator is in normal position or when deflected laterally with reference to the pin support 4. Thus a porcelain insulator proper is adapted to be used for mine trolleys and any: other places where jar, expansion, or vibration have heretofore rendered it inexpedient. the body 1 be broken from any cause, another may be quickly and easily screwed on the spring.

In screwing the pin a into a bar or other support, the tip 50f the spring comes in contact with the bar or with an interposed Should, however, 1

washer which may be applied to the pin and the friction between the spring and body of the insulator is such that the insulator is held securely. When thustightly screwed on the springthe insulator cannot be unscrewed without first compressin the lower coils of the" spring, which may efiected by forcing the free end 5 of the spring back .by means of a tool inserted between the same and the body of the pin as'shown in Fig. 4, and applying pressure to the longer arm of such ever whereby the lower coils of the spring are wound slightly closer to the pin.

.What we claim is:

The combinationof a non-conducting insulator proper having a central conical socket provided with a spiral grooveand a support for said insulator comprising a screw threaded pin and a s iral spring secured thereto at the top and encircling the bod of the pin but spaced therefrom below sai top, the spring corresponding in size and form to the socket and its lowerportion having a downward project-ion or tip 5, as and for the purpose shown and described.

PERRY S. DUMBOLTON.

FRANK FRANZ. Witnesses:

V. 0. Baownnroo, S. P. Teens. 

